Research of Groundwater Heat Source Pump in the Cold Region

A certain scale underground permafrost is chronically existing in northeast certain regions,thus forming an nature cold source and thats has a great influence on the application of groundwater source heat pump. In order to improve operational efficiency of groundwater source heat pump,the paper uses laboratory and field test and numerical simulating method to probe into influence rule of cold source on groundwater heat source pump. Author carried on thermal physical experiments and field thermal response tests of the cold source site for Jiagedaqi region. Study has shown that thermal physical parameters of sand and gravel (specific heat capacity,thermal conductivity) present discrete phenomenon with the depth in the region,thermal physical parameters of sandstone and granite have little change,thermal conductivity of granite is largest and sand and gravel is smallest and sandstone is placed in the middle,specific heat capacity has obvious fluctuation for the depth influence,specially for sand and gravel layers on the different depth. Based on geological conditions,the paper constructs numerical model and carries out numerical research,and then simulates and analyzes heat breakthrough and influence radius of pumping/injecting system of multiple well,simulating results show that influence range of cold source should be within 150m to multiple well and cold source has the greatest effect on water source heat pump less than 75m. Research results will provide theoretical basis and reference for groundwater source heat pump designing and site selection.